Montana ranks fifth in wind energy potential in the U.S., with an estimated capacity of 116,000 megawatts over 17 million windy acres. To date, the state has installed less than 300 MW of wind power, but more projects are underway.
Hoping to "spark cooperative efforts between wind energy and conservation interests, so that the promise of renewable energy can be achieved without sacrificing Montana's cultural, aesthetic, or biological heritage," The Nature Conservancy has released a 54-page study ("Ecological Risk Assessment of Wind Energy Development in Montana") cataloguing the most susceptible species in the state's windiest areas, urging that developers avoid nearly 8 million acres deemed "high-risk to ecological values."
The study says:
Montana is home to extensive intact habitats, retaining much of the species
and viewsheds first documented by European explorers. It contains some of the largest,
intact grasslands remaining in North America and more mixed-grass prairie than any
other state in the Great Plains. It also retains extensive examples of montane coniferous
forest systems that today support the most complete carnivore assemblages in the lower
48 states. Compared to most of the West, it has some of the least developed
intermountain valleys. It also is home to the nation’s longest free-flowing river and
harbors high quality aquatic and riparian habitats across the state.
Examining a range of species -- including birds, bats, deer, antelope, elk and grizzly bears -- the study notes that:
Both gas development and wind farms are characterized by extensive
road developments that fragment habitat and increase potential of vehicle collisions.
Vertical structures, transmission lines, and turbines may decrease survival or reproductive
success as a result of collisions and creation of habitat for predators. Additionally, the
structures themselves may alter habitat suitability, resulting in abandonment. One
apparent example of this was documented in Idaho, where 8 meteorological towers, 30 to
150 feet in height and topped with anemometers, were installed to measure wind velocity
for a commercial wind power feasibility study. Over a period of five years, 7 of 9 sage
grouse leks were abandoned and the overall population declined about 75%.
The study concludes that optimum places for wind development include 4 million acres already under cultivation. "Very few species use cropland," the study's author, Brian Martin, told the Great Falls Tribune. Another 5 million acres that have already been fragmented and developed also pose relatively low risk to the 30 species named in the study.
Finally, the study emphasizes that "wind energy development will ultimately need to be considered in terms of the cumulative effects. The sum of the parts will most likely be greater than each project considered individually."
For a look at how the siting of wind farms impacts the human species, see Wind Setbacks.